The difficutlty of manufacturing a Walsh driver is something that I believe could be resolved by good reengineering.
In my former life as an aerospace engineer, we worked closely with a university lab who were the primary designers of very sophisticated military electromechanical equipment. Our company's part of the design job was to refine their original designs, which often disregarded little details like "how do you make it?". The term used is "producability engineering" and it appears that the Walsh driver design never had the benefit of this kind of engineering.
In my former life as an aerospace engineer, we worked closely with a university lab who were the primary designers of very sophisticated military electromechanical equipment. Our company's part of the design job was to refine their original designs, which often disregarded little details like "how do you make it?". The term used is "producability engineering" and it appears that the Walsh driver design never had the benefit of this kind of engineering.